ADHD drugs may slow growth and delay puberty in teenage boys

Could ADHD stimulant drugs be slowing your son's growth or delaying his pubertal development? A new study suggests this may be the case.

The study, published in The Medical Journal of Australia, investigated the growth and attainment of puberty in boys with ADHD who were taking stimulant medication. Sixty-five boys aged 12 to 16 who were taking ADHD stimulants for at least three years were compared against 174 similarly aged boys who did not have ADHD (referred to as 'healthy controls').

On average, the boys taking stimulants had taken them for six years by the time the study was conducted. Researchers were provided height and weight data for each boy from the beginning of treatment (referred to as 'baseline') until the present. At baseline, the heights and weights of the boys were similar to those of healthy controls of the same age.

However, by age 12 to 14, boys who were taking stimulants for ADHD had significantly lower weight and body mass index than their peers who did not have ADHD. Likewise, by age 14 to 16, boys on stimulants had significantly lower height and weight. The higher their medication dose, the slower their growth rate was.

Also by age 14 to 16, boys taking stimulants were significantly delayed in terms of pubertal development compared to similarly aged healthy controls.

The researchers concluded that taking stimulant medication for more than three years results in a slower rate of development during puberty.

"To maintain an adequate rate of growth during puberty we recommend that boys on ADHD stimulant medication should take the lowest dose that adequately treats their ADHD," said Dr. Alison Poulton, lead study investigator and clinical senior lecturer at Sydney Medical School.